Humans and animals regularly fall ill due to microbial infections or due to a disturbance of their intestinal flora by a, usually foreign, microorganism. In the treatment of such infections, usually, antibiotics are used to remove the undesired pathogenic organisms.
A drawback of the use of antibiotics is that not only the pathogenic microorganisms, but also the useful and essential microorganisms in the intestinal flora are killed by the antibiotics. The patient is severely troubled by this, inter alia by the occurrence of diarrhea, and a period of recovery from the intestinal disturbance is necessary. There are only few antibiotics that have such a selective activity against undesired microorganisms that they can prevent the occurrence of intestinal disturbances when using antibiotics.
Another drawback of the use of antibiotics is that certain individuals exhibit allergic reactions to certain antibiotics, such as penicillin. The consequence of this is that those persons are preferably not treated with such an antibiotic and that they should avoid contact with such an antibiotic as much as possible.
Currently, antibiotics are often used in animal feed to reduce the metabolism of the intestinal flora and to improve the availability of nutrients for the host. In this manner, the meat yield can be increased. Further, antibiotics are used to control infections. However, meat from cattle treated with antibiotic is, for various reasons, not considered suitable for human consumption. Also, the milk of dairy cattle treated with antibiotic is unsuitable for human consumption. Thus, the use of antibiotics in cattle feed is under dispute and there are hardly any alternatives yet.